Ms Banks joins Oliver Yates, who is challenging Treasurer Josh Frydenberg in Kooyong, and Zali Steggall, who is challenging former prime minister Tony Abbott in Warringah, as another independent candidate seeking to galvanise voters against the Liberals after the toppling of Malcolm Turnbull last August.
Unlike those others, however, she already sits in Parliament as the member for Chisholm, centred on the Melbourne suburb of Box Hill, which she won as a Liberal candidate in 2016 before a spectacular falling out when she quit the party and moved to the crossbench over the leadership crisis and the bullying she witnessed in federal politics.
“It was a culture of terrible behaviour which was an entrenched, anti-women culture,” she said of what she saw in the Liberal Party last year.
“But also, the right wing of the Liberal Party clearly created what I call parliamentary roadblocks in relation to issues such as climate change, and climate change action in my view is an urgent imperative.”
“It was very frustrating to be in the Liberal Party and to see the benefits of the National Energy Guarantee, and then seeing that basically being used as a trigger to blow up the government.”
She will continue her electorate work for constituents in Chisholm until the election is called and she launches her formal campaign for Flinders, where she now lives with her husband after spending much of her childhood there.
Ms Banks said locals in Flinders felt they had been “taken for granted” by Mr Hunt and could not understand his decision to try to help Home Affairs Minister Peter Dutton become Prime Minister last August.
“They’re particularly angered at Greg Hunt’s role in the leadership spill, in him being Peter Dutton’s wingman and wanting to oust Malcolm Turnbull and Julie Bishop,” she said.
Mr Hunt was one of the cabinet ministers who voted for Mr Dutton in the first leadership ballot, on August 21, and then resigned in order to back Mr Dutton in the second ballot, on August 24, which was won by Mr Morrison.
Ms Banks, a former lawyer and chief counsel at companies including George Weston Foods and GlaxoSmithKline, supports many of the Turnbull government’s tax policies but breaks with the Morrison government on climate change policy.
She said she opposed Labor tax proposals including its changes to negative gearing on investment properties and its halt to cash refunds for shareholders who benefit from dividend imputation tax credits.
“This is a terrible proposal for people who aren’t necessarily high income earners but want to be self-sufficient,” she said of the Labor changes to dividend tax rules.
“In relation to negative gearing, I oppose those changes. I believe it will affect housing markets and, again, it’s not necessarily just high-income people who invest in the housing market.”
If elected and confronted with a hung Parliament where she must support either Labor or the Coalition, Ms Banks said she would make her decision on the “context at the time” rather than indicating beforehand which side she would back.
On preference deals ahead of the election, she said she wanted to issue an “open ticket” without advising voters to give their second preferences to one party or another, but she also said she would keep her options open to do the best for her campaign.
Speculation about Ms Banks has been building for months. She said she made her decision to run for Flinders over the summer, after her decision last year not to recontest Chisholm.
Mr Hunt said he had treated Flinders as “completely marginal” from the first day he had put himself forward to run for the seat.
“I’ve just walked 500 kilometres around the electorate and that’s part of the passion of visiting 50 schools and 50 towns over a three-week period and working for autism, working and meeting with families,” he said on Wednesday.
Mr Hunt said he was fighting for better cancer services in the local area, an upgrade to Rosebud Hospital and the electrification of the Baxter railway line.
“Labor is opposing the electrification at state level of the railway to Baxter, which is short changing Peninsula residents. So there are the things we’re fighting for,” he said.
David Crowe is Chief Political Correspondent of the Sydney Morning Herald and The Age.